No dollar figure was put on the purchase, which at today's trading price equals some $A23.81 million.

Starting today, China Southern Airlines is offering direct daily flights to China from Auckland.

Singapore Airlines has joined the Sustainable Aviation Fuel Users Group, in what the company says is another step in its committment to reducing greenhouse gas emissions.

Singapore Airlines has grounded three of its Airbus A380 jumbo jets after carrying out an inspection on the planes' engines, according to media reports that have yet to be confirmed by the airline.

The airline says the three planes will be fitted with new engines as a precautionary measure.

Like Qantas, which has grounded its fleet of six A380s after a mid-air explosion in an engine of one of its planes forced emergency landing last week, Singapore uses Rolls Royce-manufactured engines.

An international safety warning was issued in August about the Rolls Royce engines used aboard the Qantas A380 super jumbo forced to make an emergency landing at Singapore yesterday after an engine exploded.

However, Emirates, which operates the only A380 service in and out of New Zealand, uses a different engine.

The engine used on the Emirates A380, which flies daily in and out of Auckland, is an Engine Alliance GP7200.